Actuator mechanism



May 13, 1969 H. M. FREDERICK 3,443,444

' ACTUATQR MECHANISM Filed June '7, 1967 23 27 FIGI 19 FIG 4- 4-- CCD co: 4

I I 31 /0 23 21 35 O INVENTOR.

HAYROLD M. FREDERICK ATTORNEY United States Patent 3,443,444 ACTUATOR MECHANISM Harold M. Frederick, Birmingham, Mich., assignor to Burroughs Corporation, Detroit, Mich., a corporation of Michigan Filed June 7, 1967, Ser. No. 644,287 Int. Cl. F16h 25/08 US. CI. 74-54 6 Claims ABSTRACT OF THE DISCLOSURE An electro-mechanical actuator mechanism having drive means such as an eccentric drive providing a source of motion for actuating a member. Interposed between the member to be actuated and a control source, such as a solenoid, is an operating lever. The drive means acts upon this lever causing it to selectively pivot about either one of two fulcrums. One of the fulcrums is located at the point of connection between the lever and the member to be actuated and the other of the fulcrums is normally retracted, but movable to engage the lever by the control source such as a solenoid. A second lever is connected to the operating lever for directing a force component against the retractable fulcrum to disengage it from the operating lever.

BACKGROUND OF THE INVENTION Field of invention This invention relates to actuator mechanism in general and to means for directing a portion of the actuating action for positively deactuating the mechanism.

Prior art Prior art devices rely upon the spring force of a coiled tension spring or the like to restore the armature of the solenoid. Often time the force rate of the spring must be a compromise between the force required to overcome th residual magnet-ism of the solenoid and the maximum force allowable to permit the operation time of the solenoid to be acceptable. Also inherent in this type of mechanism, is a significant friction factor at the hinge point of the armature and the solenoid frame. As a consequence, the residual magnetism and friction retains the armature and causes malfunction.

In order to insure satisfactory armature disengagement, an external linkage system has been used to forcibly disengage the arrnature from its magnet.

SUMMARY OF INVENTION The invention disclosed herein provides means, such as a lever, which is connected to deflect a component of the output action of the actuator mechanism toward the retracted position of the armature. When the actuator mechanism is non-actuated, the lever opposes any movement in the output. By the selection of the mounting angle of the lever relative to the operating lever of the actuator and the length of the lever, the magnitude of the deflected force component can be controlled.

It is, therefore, a principle object of the invention to positively disengage the armature of a solenoid without the need of an external linkage system.

Another object of the invention is to achieve position disengagement of the armature from the solenoid Without any increase in the operate time of actuator mechanism.

DESCRIPTION OF DR'AWINGS The invention, both as to its organization and method of operation, will best be understood by reference to the 3,443,444 Patented May 13, 1969 following detailed description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a side view of an actuator mechanism with its parts shown in their normal positions;

FIGURE 2 is a view similar to FIGURE 1, but with the parts shown in operating positions;

FIGURE 3 is a modification of the preferred embodiment, showing the operating parts in their normal positions;

FIGURE 4 is a view similar to FIGURE 3 with the operating parts shown in operating positions.

DETAILED DESCRIPTION Referring to FIGURE 1, there is shown an actuator mechanism comprising a solenoid 11, an operating lever 13, and an eccentric drive means 15.

The solenoid 11 is a conventional unit having a coil 17, a frame 19, a first retractable fulcrum or armature 21, and a retainer spring 23. The coil 17 of the solenoid 11 may be connected to a source of electrical power, such as a battery (not shown), through various control means such as a switch .(not shown) for operating the solenoid 11. The retainer spring 23 keeps the armature 21 in a retracted position away from the core 25 of the solenoid. The spring 23 is connected between one end of the armature 21 and a stud 27 which is anchored in the frame 19.

The operating lever 13, as shown in its normal position in FIGURE 1, is positioned adjacent one end 29 of the armature 21 and extends in a direction away from that end 29. As shown in FIGURE 1, the lever 13 has a free end 31 and a second and movable fulcrum point 33. Positioned adjacent the free end 31 of the lever 13, and in such a manner as to support the lever 13, is a fixed stop 35. The stop 35 serves to retain the lever 13 in its normal position. Connected to the lever 13 at the fulcrum 33 is an output member 37. This member 37 merely serves as an illustration of a use of the actuating mechanism.

Mounted below and in operative contact with the lever 13 is an eccentric drive means 15. The use of an eccentric cam 39 mounted on a drive shaft 41 is only one of several means for causing the lever 13 to pivot about the fulcrum 33. Other such means include, by way of illustration and not limitation, reciprocating means. pulsating means, etc.

Pivotally connected to the lever 13 at the fulcrum point 33 is a force tran'smiting member 43. This member 43 is conneced to a fixed pivot point '45 at the end opposite the fulcrum 33.

FIGURE 3 is a modification of the preferred embodiment shown in FIGURE 1. Similar elements in both embodiments have the same reference character except that in FIGURE 3 and FIGURE 4 the reference characters are indicated by a prime notation. The operating lever in FIGURE '3 is 13', the retractable fulcrum is 21', the eccentric drive means is 15', the fulcrum is 33', the fixed stop is 35, and the force transmitting member is 43, etc.

OPERATION The preferred embodiment of the actuator mechanism, as shown in FIGURE 1, is characteristically referred to as a see-saw actuator mechanism with the addition of the member 43. The center of gravity of the lever '13 is positioned at a point between the eccentric drive means 1'5 and the fulcrum 33. As the drive shaft 41 rotates the eccentric cam 39, the free end 31 of the lever *13 points in an arcual path about the fulcrum 3-3.

The inertia of the lever '13, the inertia of the member 43, and the biasing of the spring 44 yieldably oppose any movement of the fulcrum 33 during this time. If the drive shaft 41 is considered as the main timing member 3 of a mechanism, it is shown that the output member 37 is not indexed while the solenoid 11 is not energized.

The free end 31 of the lever 13 is shown as having a step. The purpose of this step is to form a location for the armature 21 to fit into when the solenoid 11 is actuated.

In FIGURE 1, there is shown by phantom lines, the actuated position of the armature 21 when the solenoid 11 is actuated. By moving the armature 21 into contact with lever 13, the lever 13 will then pivot about the end 29 of the armature 21.

As the cam 39 rotates toward its high point with the armature 21 in operative contact with the lever 13, the fulcrum point 33 will move in an arcual path about the end 29. Since the member 43 is pivotally connected to the lever 13 at the fulcrum 33, it too moves in an arcual manner about its fixed pivot 45. Since these two pivots are not coincident, either the lever 13 must slidably move along the fixed stop 35, or the arm 43 must be disengaged from the lever 13. As previously state, it is an object of the invention to positively disengage the armature from the solenoid and, therefore, the arm 43 is prevented from becoming disengaged causing the lever 13 to slide to the left as viewed in the drawings.

In FIGURE 2, there is shown an actuated position where the acute angle has increased to some angle 0 In this position the solenoid can be de-energized to allow the armature 21 to be retracted. Due to the presence of residual magnetism, or a high friction hinge point, or a weak spring 23, or any combination of the aforementioned factors, the armature may be slow or very sluggish in its response.

The counterclockwise rotation of the member 43 about its pivot 45, initiates a movement of the lever 13 to be directed toward the plane of the armature 21. Since both the lever 13 and the armature 21 are in physical contact with each other, a force which is transmitted by the movement of the lever 13 against the armature 21 causes the armature to move toward its retracted position. Thus the function of the member 43 may be briefly described as an armature restorer.

The initial size of the acute angle 0 determines the amount of horizontal movement of the lever 13 resulting from the rotation of the cam 39 and the counterclockwise rotation of the member 43. The smaller the angle the smaller the displacement of the lever 13. When the cam nears the completion of its rotation, the armature 21 will be freed from the lever 13 due to the force of the spring 23 and the removal of the contact friction between both the lever 13 and the armature 21.

FIGURES l and 2 show the preferred embodiment of the actuator mechanism having a moveable fulcrum. In FIGURES 3 and 4, the fulcrum 33' is fixed. Thus, as the eccentric drive means rotates with the retractable fulcrum 21' in its normal position, as shown in FIGURE 3, the lever 13' pivots about the fulcrum point 33. But when the retractable fulcrum 21' is operatively connected to the lever 13', the rotational movement of the eccentric drive means 15' will cause the lever 13 to pivot about its free end 31'. The rotational movement of the member 43 from an angle 6 to 0 will direct a component of force against the retractable fulcrum 21' of sufficient magnitude to disengage it from the lever 13'. In this embodiment, the lever 13' moves relative to the fixed fulcrum 33.

The retractable fulcrum 21 in FIGURES 3 and 4, may be actuated by any known means such as a solenoid, a valve, by hand, etc. The invention is not limited by the manner in which the retractable fulcrum is actuated.

It will be apparent that many changes and modifications of the several features described herein may be made without departing from the spirit and scope of the invention. It is, therefore, apparent that the foregoing description is by way of illustration of the invention rather than limitation of the invention.

While a particular embodiment of the invention has been shown, it will be understood, of course, that it is not desired that the invention be limited thereto since modification may be made, and it is, therefore, contemplated by the appended claims to cover any such modification as fall within the true spirit and scope of the invention.

What is claimed is:

1. An actuator mechanism comprising:

a first fulcrum,

an operating lever having a free end, said operating lever being pivotal on said first fulcrum and being moveable relative thereto,

a second and normally retracted fulcrum moveable into effective engagement with the free end of said operating lever,

means operatively connected to said operating lever for pivoting said operating lever on said second fulcrum when the latter is in engagement with the free end of said operating lever, and

a force transmitting member operatively connected to said operating lever to move said second fulcrum toward retracted position by the pivoting action of said operating lever by said means.

2. An actuator mechanism according to claim 1 Wherein said force transmitting member is a lever pivotally connected at one end thereof to said operating lever and having a fixed pivot at the other end disposed between said free end of said operating lever and said second fulcrum.

3. An actuator mechanism according to claim 1 wherein said force transmitting member is a lever and forms an acute angle with said operating lever.

4. An actuator mechanism according to claim 1 wherein said first fulcrum is moveable with said operating lever and said force transmitting member is connected to said operating lever at a point coincident with said first fulcrum.

5. An actuator mechanism according to claim 1 wherein said first fulcrum is moveable with said operating lever and said force transmitting member is connected to said operating lever at a point coincident with said fulcrum and yieldable means operatively connected to said operating lever for opposing movement of said first fulcrum, when said second fulcrum is retracted.

6. An actuator member according to claim 1 wherein said operating lever is supported by a fixed stop member positioned between said means and the free end of said operating lever and said force transmitting member retains said lever against said stop in said levers normal position.

References Cited UNITED STATES PATENTS 719,390 1/1903 Stockall 7454 819,649 5/1906 Ham 7454 934,902 9/1909 Evans 7454 2,603,096 7/1952 Clark 7454 FRED C. MATTERN, JR., Primary Examiner.

W. S. RATLIFF, JR., Assistant Examiner.

US. Cl. X.R. 74567 

